Head gasket "shim?"

[Chuck!]

I have vortec heads with a 64 cc chamber, and Im reluctant to get them milled to 58 cc to save my compression. Hot rod used this gasket in their buildup (pn FPP-1094):

Chevrolet: 262-350, steel shim, .015 in. compressed thickness, 4.100 in. gasket bore, 3.2 cc compressed volume, head gasket

to help save their compression, although they did get the heads milled.

Is this OK for a head gasket? It seems way too small, and I dont want to be replacing head gaskets once a year!

Thanks!

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Chuck Kulchar
1991 Camaro RS LO3 A4
15.823 @ 85.84 MPH
Project sLO3

[Damon]

It's what the factory used for YEARS in their assembly line engines. It will work fine IF both surfaces are VERY flat. No more than .003" warpage in the heads and deck COMBINED or they'll never seal up. They are very unforgiving of warped mating surfaces.

[firechicken_3]

how much can this head gasket raise compression from a .040 gasket? ,

and what is the normal cost for having a set of heads milled?

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Pics of the Firebird


84' Firebird, 305ci lg4, 700R4, 288/292 duration .450/.460 lift,Edelbrock Performer intake, Holley 600cfm 4 barrel, K&N, Pacesetter Headers, 3' exhuast, dual tips directly behind the rear wheels, no cat,Motive 3.73's and Auburn Posi
1/4mile 15.17sec @ 92.5mph

[GMTech]

.015 is VERY thin, and like mentined, is very unforgiving.

I installed 67cc Trick Flow Heads on my car and to help w/ compression, I installed GM P/N: 10105117 Its a composition gasket, so its a little more forgiving, and its safe for Alum or Cast Iron. ITs compressed thickness is .028" I've put several thousand miles on this setup, including over 20 passes at 1/8 and 1/4 mile tracks, still working great.

One thing to mention though, as the head gaskets get thinner, the heads sit lower on te head, and therefore bolt holes won't always line up. I had to elongate my intake bolt holes to match up to my head.

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Webmaster:SETHIRDGEN
GM Tech
ASE Master Auto Technician + L1
1987 Trans Am: 357ci
Ported TFS heads, ZZ4 cam, headers & exhuast and other go fast goodies
13.53 @ 103.77

[bjankuski]

The 1094 gasket has worked very well on all of the engines that I have used it on. That is the exact gasket I am using on my 305 with Vortec heads. I have had not to elongate the holes on my intake when I have used this gasket on any of the engines. Whenever I have used this gasket on a used engine I have used a gasket dressing to help with the seal. The gasket dressing that I have used is Hylomar and I have never had any problems. One other note, I am not easy on my engines, I have probably run 200 plus drag strip passes and many dyno sessions with this gasket and never had a failure.

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1988 Formula 5L/5sp 3.45 gears, SLP cold air kit, MAS gutted, TPIS air foil, TPIS AFPR, MAC headers, Mac under drive pulleys, MAC cat back, Relocated MAT, Vortec heads, Vortec intake, ZZ-4 cam.
Best ET street tires 13.53
Best 60 FT street tires 1.903
Best MPH street tires 100.92
255.4 RWHP = Approx 300 flywheel
314 RWTQ = Approx 369 flywheel

[IrocSS85]

I used the 1094 shim too and its still sealing after more then a thousand mi.s. I did check to see if the deck and head were warped, but dont think I used .003 as a standard. that sounds less then I checked for. I did use a gasket dressing too. I didnt have to elongate any holes either. I figured worst case scenario Id have to change to the .028" gaskets.
chris

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1985 Iroc Z, (parting out, email for parts)

1986 Iroc Z, (up and running, but still lots of work to do)
355, ported camel hump heads,750 holley, 700r4, 10.5 compr., forged flat tops, solid cam .501I .510E, 4gen rear w/3:73posi,girdle, and disc's, Edel. torker II, shift kit, 3500 stal, hedmann LT. headers, 4 gen seats, man. strg., lt1 starter, alum. w/p, msd :6al, coil, dist., mallory wires. exp high 12's-low 13's

1995 z28,SS Hood, Iroc style spoiler, tints and black outs, 700r4,2400 act. stall speed,B&M hammer shifter, 17" budnick trilogy III wheels, 275/40 ZR17, 160 stat, man. cooling fan sw., homemaid CAI,1LE elbow, hypertech airfoil, t.b.bypass,!cat, flowmaster, !maf screen, relocated batt., 1LE front l.c.a.s', poly trans and torq.arm bushings, MSD 6AL, custom program, p&p maf, accel coil, and under drive pulley

mods that i have, just not on car yet:
msd wires, edelbrock mid. headers, edelbrock rpm catback

[Chuck!]

Wow, thanks everyone for the input!